| AVS 60th International Symposium and Exhibition | |
| Thin Film | Wednesday Sessions |
| Session TF+AS+NS+SE-WeA |
| Session: | Beam and Glancing Angle Deposition (GLAD) Techniques |
| Presenter: | L. Cao, University of Birmingham, UK |
| Authors: | R.E. Palmer, University of Birmingham, UK L. Cao, University of Birmingham, UK W.D. Terry, University of Birmingham, UK F. Yin, University of Birmingham, UK |
| Correspondent: | Click to Email |
Atomic clusters are attracting a great deal of attention because of their remarkable size-dependent properties and the corresponding potential applications which arise, e.g. in catalysis, nanomaterials, biochips [1][2]. However, the advancement of this field is limited by the low cluster fluxes, ~ 1nA, currently available [3]. Here we demonstrate a radical new instrument, the Matrix Assembly Cluster Source (MACS), with the potential to produce size-selected clusters in great abundance (up to ~1A, i.e. an increase of 9 orders of magnitude). In this new approach, the atoms of the desired cluster material (e.g. Au or Ag) are trapped in a thin matrix of condensed rare gas atoms (e.g. Ar). Clusters are then produced by collisions in the matrix which are driven by an atomic ion beam (such as Ar+) in the transmission sputtering regime.
The transmission sputtering of the matrix is monitored in real time by ion-induced luminescence while the noble metal clusters produced and deposited are analyzed by aberration-corrected scanning transmission electron microscopy (STEM): the number of cluster atoms is measured by the integrated HAADF intensity [4][5]. The results demonstrate the production of Au and Ag clusters by the new method and show that the distribution of cluster size, even before mass selection, is narrow under certain experimental conditions. We find the mean size of the clusters is mainly determined by the concentration of metal atoms in the condensed rare gas matrix. The size distribution and flux of clusters also depends on the ion beam energy.
[1] J. V. Lauritsen, J. Kibsgaard, S. Helveg, H. Topsoe, B.S. Clausen, E. Laegsgaard and F. Besenbacher, Nature Nanotechnology, 2, 53 (2007)
[2] R.E. Palmer, C. Leung, Trends Biotechnol, 25, 48, (2007)
[3] S. Pratontep, S. J. Carroll, C. Xirouchaki, M. Streun, R. E. Palmer, Rev. Sci. Instrum.76, 045103 (2005)
[4] Z.Y. Li, N.P. Young, M. Di Vece, R.E. Palmer, A.L. Bleloch, B.C. Curley, R.L. Johnston, J. Jiang, J. Yuan, Nature, 451, 46, (2008)
[5] Z. W. Wang, R. E. Palmer, Nano Letters, 12, 91, (2012)
Corresponding Author: R.E.Palmer@bham.ac.uk